Use the interactive number line to find each difference to complete the table. A 4-column table with 4 rows. Column 1 is labeled a with entries 1, negative 1, negative 4, negative 6. Column 2 is labeled b with entries 2, negative 2, 1, negative 3. Column 3 is labeled a + b with entries 3, negative 3, negative 3, negative 9. Column 4 is labeled a minus b with entries negative 1, U, V, W. U = V =